US3810810A - Apparatus to continuously provide fabric with a heat sealed selvage - Google Patents

Abstract

Machine and process to continously heat seal a strip of thermoplastic film material to a roll of textile material in the longitudinal direction thereof and sever said strip of thermoplastic film and said material to provide at least two widths of material with sealed edges to prevent unraveling.

Description

May 14, 1974 BYLUND ETAL 3,810,810

- APPARATUS T0 CONTINUOUSLY PROVIDE FABRIC WITH A HEAT SEALED SALVAGE 8 Sheets-Sheet 1 Original Filed June 20. 1969 INVENTORS v DON M. BYLUN D VlCTORI W. Kl MBLE ATTORNEY? y 14, 1974 D. M. BYLUND E AL 3,310,310

APPARATUS TO CONTINUOUSLY PROVIDE FABRIC WITH A HEAT SEALED SALVAGE Orlgmal Flled June 20, 1969 8 Sheets-Sheet 2 INVENTORS DON M.BYLUND VICTIOR W.KIMBLE ATTORNEY y 14, 1974 D. M. BYLUND ETAL APPARATUS To CONTINUOUSLY PROVIDE FABRIC WITH A HEAT SEALED SALVAGE Original Filed June 20. 1969 8 Sheets-Sheet 3 E L $0 N mum wu NEW A R N m DV MIL/"1AM ATTORNEY May 14, 1974 D. M. BYLUND ET AL APPARATUS TO CONTINUOUSLY PROVIDE FABRIC WITH A HEAT SEALED SALVAGE Original Filed June 20. 1969 8 Sheets-Sheet 4.

INVENTORS DON M.BYLUND VICTOR W.K|MBLE ATTORNEY May 14, 1974 o. M. BYLUND ETAL 3,8W,1

APPARATUS T0 CONTINUOUSLY PROVIDE FABRIC WITH A HEAT SEALED SALVAGE Original Filed June 20. 1969 8 Sheets-Sheet 5 FIG '8- Flax-- INVENTORS DON WLBYLUND VICTOR W.K|MBLE ATTORNEY May 14, 1974 D, M BYLUND ETAL 3,810,810

APPARATUS T0 CONTlNUOUSLY PROVIDE FABRIC WITH A HEAT SEALED SALVAGE Original Filed June 20. 1969 8 Sheets-Sheet 6 INVENTORS DON M. BYLU ND VICTOR W.KIMBLE M {KM ATTORNEY May 14, 1974 D, M. BYLUND ETAL 3,810,810

APPARATUS T0 CONTINUOUSLY PROVIDE FABRIC WITH A HEAT SEALED SALVAGE Original Filed June 20. 1969 1 8 Sheets-Sheet '7 FIG. -/4- INVENTORS DON M. BYLU N D VICTOR W. KIMBLE 44 M! Wm ATTORNEY May 14, 1974 D. M. BYLUND ETAL 3,810,810

APPARATUS TO CONTINUOUSLX' PROVIDE FABRIC WITH A HEAT SEALED SALVAGE Original Filed June 20. 1969 8 Sheets-Sheet 8 FIG. -15- Q) (I) m INVENTORS DON M.BYLUND VICTOR W.KIMBLE Mam ATTORNEY United States Patent US. Cl. 156 -499 3 Claims ABSTRACT OF THE DISCLOSURE Machine and process to continously heat seal a strip of thermoplastic film material to a roll of textile material in the longitudinal direction thereof and sever said strip of thermoplastic film and said material to provide at least two widths of material with sealed edges to prevent unraveling.

This is a division of application Ser. No. 834,969, filed June 20, 1969.

This invention relates generally to methods and apparatus for forming a thermoplastic type selvage in a textile material and more particularly to methods and apparatus for continuously forming from a roll of material such items as diapers, handkerchiefs, etc., which are automatically sealed with a thermoplastic film and cut from the roll to provide sealed selvages to prevent unraveling.

'Prior to this invention it was known to heat seal a strip of thermoplastic material transverse to the longitudinal direction of a roll of fabric and out such seal substantially in the center thereof to form individual sealed edge products. An example of such a machine is shown in Us. Pat. 3,385,747 wherein a roll of fabric is sealed in the weft direction. This machine takes single width fabric with woven selvages in the warp direction and provides a prodnet with only'two sealed edges. Economically, it is desirable to take wide widths of fabric and seal longitudinal portions thereof and then sever the sealed portions substantially in the center thereof to provide a plurality of longitudinal extending sealed separated strips of fabirc. These portions can then be automatically supplied to a machine which simultaneously transversely seals all the separated strips in the weft direction and then simultaneously severs the separated strips substantially in the center of the transverse seals to provide a plurality of individual textile products with edges sealed to prevent unraveling of the selvages.

Therefore, it is an object of the invention to provide a method and appartus which automatically provides a plurality of sealed edge products from a single width of fabrics.

Another object of the invention is to provide a method of and apparatus to apply a thermoplastic material in the longitudinal direction of a fabric to produce a product which has the longitudinal edges thereof sealed.

Other objects and advantages will become readily apparent as the specification proceeds to describe the invention in which:

FIG. 1 is a schematic representation of the preferred method and apparatus to produce a sealed edge product;

FIGS. 2 and 3 show products produced by the apparatus shown in FIGS. 1 and 4;

FIG. 4 is a'blown-up side view of the longitudinal sealing apparatus shown in FIG. 1;

FIG. 5 is a front view of FIG. 4;

FIG. 6 is a side view of the fabric lifter shoe;

"FIG.'-7 is a cross-sectional view of the fabric preheater in-tlie fabric heating position;

FIG. 8 is a view similar to FIG. 7 with the fabric preheater in the inoperative position;

FIG. 9 is a cr0ss-sectional view of a modified fabric preheater;

FIGS. 10 and 11 are schematic: views of the fabric preheater of FIG. 9 in the active and inactive position;

FIGS. 12-14 show a second alternative fabric preheat system; and

FIG. 15 is a schematic view of the longitudinal sealing machine when the fabric is taken up after slitting.

In the preferred form of the invention sealed edge fabrics are being produced continuously from a roll of.

material. A roll of fabric of sufilicient width to produce two of a desired product such as diapers, towels, etc., has

a strip of thermoplastic film such as polyvinyl chloride,

nylon-6, etc., heat sealed thereto in the longitudinal direc-' tion of the fabric. Then the fabric is slit in the middle of the seal to provide two lengths of fabric and, preferably,;

supplied continuously to a machine which heat seals another strip of thermoplastic film across the whole width of each the lengths of fabric. As with the above-mentionedlongitudinal seal, the film material can be polyvinyl chloride, nylon-6 or any other suitable material. Each of the.

lengths of fabric are then cut approximately in the center. of the seal across the width thereof to provide a sealed edge product. Normally the longitudinal direction of the, fabric is the warp direction and the width of the roll of;

fabric is the fill or weft direction.

FIGS. 2 and 3 represent products obtained from the cycle of the machine. It is obvious that two products like FIG. 2 or 3 can be obtained depending on whether none,

one or two of the selvages of the roll of fabric 14 are,

finished or hemmed prior to introduction into the maf chine.

verse position of which is controlled by a conventional. edge guide device. Briefly, the edge guide device consists of a sensing element 18 which senses the edge of the fabric 14 and if the edge of the fabric 14 is not properly positioned a signal will be relayed to the control member 20 to move the dolly in one direction or the other. In the preferred form of the invention, the system employed isv hydraulic and the dolly 16 is moved back and forth by a hydraulic piston. Such a system is conventional and per se is not part of the invention.

In the preferred form of the invention, the fabric 14 passes under idler rolls 22 and 24 into the nip of feed rolls 26 and 28 from whence it is supplied under dancer; roll 30 and idler roll 32 into the nip of seaing rolls," generally designated 34 and 36. Preferably the rolls 34 and 36 are driven at a speed slightly faster than the nip rolls 26 and 28 in order to maintain a predetermined tension in the fabric between the two pairs of rolls.

Dancer roll 30 automatically controls the speed of roll 26 depending on the vertical position of the dancer roll in a manner such as that disclosed in US. Pat. 3,385,747.

As discussed briefly before, it is preferred to provide seals on the fabric made from suitable thermoplastic polymer film such as polyvinyl chloride, nylon-6, etc. In the use of such films certain variables have to be taken into Patented May 14, 1974 In FIG. 1 the overall machine to produce the product'sjj of FIGS. 2 and 3 is schematically shown. The roll of fabric 14 to be sealed is supported on a dolly 16, the trans;

consideration such as the pressure exerted on the filmfabric sandwich in the sealing nip, the temperature of the hot surfaces of the nip, the temperature of the fabric entering the nip, the temperature of the film entering the nip, thickness and construction of the fabric, thickness and constituency of the film, the speed at which the fabric passes through, the tension of the fabric and the tension of the film entering the nip. Also it is felt that the temperature of the film in the hot nip must be at least at the softening point to allow the polymer to flow into the fabric. As an example the softening temperature of a 3.5 mil thick polyvinyl chloride pasticized polymer film is about 350 F. To provide the best means to maintain such temperature it is felt that the temperature and speed of the fabric and film coming together at the nip of rolls 34 and 36 should be controlled. If these variables are not controlled, various defects in the seal will occur depending on the type of variance. For example, if the film is not sufiiciently warm, the fiow into the fabric may be insufficient and poor seal adherence may result. If the fabric temperature is not sufiiciently high, or if the hot surfaces of the pressure nip, are not at a sufficiently high temperature, the fabric and film will be quenched at some temperature below the softening point and again poor seal adherence will result. Conversely, if the fabric temperature exceeds the desired temperature to an extent that the fabric becomes dehydrated discoloration of the fabric can result. In the use of polyvinyl cholride, the film temperature prior to entering the nip must be such that it does not approach the softening temperature to prevent loss of dimensional stability and consequently the production of irregular seals. Further, the pressure at the nip has to be sufi-lcicnt to cause the softened film to adequately penetrate the fabric.

It can be readily seen from the above that certain conditions must be met once the fabric and film have been selected. As previously discussed, the fabric 14 is delivered from the nip rolls 26 and 28 to the nip of roll members 34 and 36 at a pre-determined tension and speed. Depending on the speed selected the fabric can be pre-heated in the area of the longitudinal seal by pre-heater 38 above and below the fabric. Pre-heaters 38, preferably, are infrared elements which provide radiant energy for pre-heating of the fabric. schematically shown are pneumatically actuated pistons 40 which are actuated by a fabric temperature sensing device, not shown, to actuate members 41 to open and close shutters on the pre-heaters 3-8 in response to the temperature sensed to control the heat supplied to the fabric. At slow fabric delivery speeds such as 12-14 yards/ min., pre-heaters 3'8 normally would not be actuated since the fabric has sufficient time to be heated by the hot portion of the roll members 34 and 36.

Roll members 34 and 36 consist of rubber covered carrier rolls 42 and cast iron heated rolls 44 and 45 to heat seal the film 46 into the fabric 14. Preferably, the cast iron rolls are heated by electrical cartridge heaters (not shown). Cast iron rolls 44 and 45 are preferably treated with a release agent such as silicone to provide the hot roll surfaces with improved release properties. The number of cast iron rolls employed is dependent upon the number oflongitudinal seals laid upon the fabric. In the preferred embodiment, since it is desired to lay down two seals 48 two pairs of cast iron rolls 44 and 45 are employed. To provide controlled nip pressure to the rolls 42, 44 and 45 yoke members 48 and 50 are pivotally secured at 52 and held in nip forming relationship with the lower rolls by the application of pressure from the pneumatically actuated cylinders 54. semicircular fabric lifter members 56 actuated by pneumatically actuated cylinder 58- are provided to lift the fabric 14 off the lower hot rolls 44 when the upper rolls 42 and 45 have been automatically pivoted away from the lower rolls when the machine is stopped.

The film 46 to be sealed to the fabric is provided in roll form on film carriers 60 mounted on the machine. Preferably the carriers 60 contain more than one film roll 62 so that the application of film to the fabric can be continuous so that one roll of film can be automatiaclly threaded upas another roll is running out. The film 46 is supplied over an adjustably mounted roll 64 onto the hot surface of the upper hot roll 45 prior to entrance into the nip of the rolls 44. The amount of wrap of the film 46 around the upper roll 45 is dependent on the amount of pre-heat necessary for the film to be heated to a molten state without it losing its form or continuity and is a function of roll speed, not roll temperature and film properties. This amount of wrap is controlled by the position of the roll 64 relative to the peripheral surface of the upper hot roll 44.

As pointed out before, the lower roll member 34 is driven so that the fabric 14 is drawn into the nip of the rolls 42, ,44 and 45 as the molten film 46 is applied thereto;

and penetrates the fabric 14 due to the pressure between the upper and lower hot rolls 44. In the preferred form of the invention the fabric from the longitudinal sealing machine is supplied to another mechanism which also places a transverse seal upon the fabric but it is within the scope of the invention to take up the fabric on a suitable takeup roll after it has been scaled longitudinally and cut. It has been found that when the fabric is supplied to a transverse sealing mechanism there is sutficient time for the longitudinal seal to set so additional cooling is not necessary since the production rate of the transverse sealing mechanism is comparatively slow. If it is desired to take up the fabric immediately after longitudinal sealing and cutting, cooling cans or rolls should be used in order to set the seal before take up.

As shown in FIG. 1 the fabric 14 with the longitudinal seals 49 thereon passes over a pair of fixed bars 66 and 68v to a pair of score cutters 70 and 72, the cutting pressure of which is controlled by pneumatic pistons 74 and 76. As is well known in the art, score cutting, a cutting edge bearing on a hardened surface, '77, has a squeezing type separation, which when applied to a still plastic seal forces the seal around the severed yarns. The fixed bars 66 and 68 tend to squeeze out and smooth out the surface of the longitudinal seal 49 so that the cutters 70 and 72 do not pick up portions of the still tacky seal. Thusly, it is an advantage to slit the longitudinal seals 49 by score cutting immediately downstream of the seal application zone because of easy registry of the cutter to the seal and quality of the sealed edge. a

The tension is maintained on the fabric 14 after passage through the nip of roll members 34 and 36 by a pair of nip rolls 78 and 80 driven at a speed slightly higher than the speed of the roll members 34 and 36. Nip rolls 78 and 80 and roll members 34 and 36 preferably are driven continuously by the same motor as rolls 34, 36, 78 and 8t) and the dancer roll 30 can then be eliminated since the dancer roll 82 which controls the speed of the abovementioned in a manner similar to that disclosed in US. Pat. 3,385,747 will then also control the speed of rolls126 and 28. Dancer roll 82 within a narrow range also acts as From the dancer roll 82 the longitudinally sealed fabricll4 is supplied under an idler roll 84 to the nip of theintermittently driven input rolls 86 and 8801: the transverse sealing mechanism of the machine. The input nip rolls 86 and 88 and the output nip rolls 90 and 92 are driven by pneumatically actuated piston 93 which when-- actuated pulls the chain 94 to the left against the bias of spring 96 to rotate sprocket 98 which in turn through suitable mechanical linkage rotates the bottom rolls 86 and 90 a predetermined distance in one direction only. The predetermined distance of rotation of the rolls 86 and 90 determines the length of fabric between transverse seals and can be adjusted to obtain various length products by adjusting the stroke of the piston 93, Located under the fabric 14 between the input and ojutput rolls is acoutinuously rotating apron system 100 for reasons herein- V after explained. To prevent the fabric 14 from engaging the upper surface of the apron system 100 when the fabric 14 is held between the nips of the input and output rolls the nip of the output rolls 90 and 92 are located slightly higher than the nip of the input rolls 86 and 88. To prois held between the nip rolls 86 and 88 and 90 and 92. The fabric 14 is now in the position to have a transverse seal placed thereon. When the fabric 14 has been moved to the position shown or just before the fabric reaches this position the piston 104 is actuated to advance a strip of film material from the roll of film 106 on the film feeding mechanism generally designated 108. The film feed and upper platen assembly 109 are identical to and operate in the same manner as that shown in US. Pat. 3,385,747 to place the strip of advanced film onto the fabric and heat seal same thereto. In other words, the upper platen-110 is actuated to a downward position onto the film material and fabric and cooperates with the lower platen 112 to heat seal the film to the fabric. Then the piston 104 .is actuated in the opposite direction to pivot the film feed mechanism back to its original position and the upper platen is lifted up off the newly formed sealed fabric portion. It should be noted at this point that upper platen 110 is fixed relative to lower platen 112 and that upper blade 116 is fixed relative to the lower blade 118 so that when the platen support member 120 is pivoted the platens and blades move together. When the upper platen 110 is retracted the piston 122 is actuated to pivot the platen support member 120 to move the platens and blades counter-clockwise to a position Where the knife blades 116 and 118 are over and under the previously formed transverse seal. Then the piston 124 is actuated to bring the upper knife 116 blade downwardly to cooperate with the lower knife blade 118 to sever the fabric 14 substantially in the center of the seal. Then the upper blade 118 is retracted and the platen support member 120 pivoted back by the piston 122 to the position shown in FIG. 1. When the platen support member 120 has returned or almost returned to the position shown in FIG. 1 the piston 93 is actuated to rotate the rolls 86 and 88 and rolls 90 and 92. Actuation of output rolls 90 and 92 causes the completed sealed edge products 10 to be delivered to the endless conveyor which deposits them in a suitable container or stacking device. As discussed before, apron system 100 is driven continuously but does not contact the fabric 14 in the position shown in FIG. 1 but the fabric 14, when severed by the blades, will tend to drop onto the aprons. Then when the rolls 86 and 88 are actuated the aprons will guide the fabric 14 into the nip of rolls 90 and 92 for the next operation. Then the herein described operation is successively repeated to provide a plurality of sealed edge products.

Looking now to some of the features in detail, FIG. 6 shows the fabric lifter member 56 in greater detail. Lifter members 56 are pivotally secured on both sides to an arm 125 of the hot roll 44 which is secured to roll support members 126 mounted on the I-beam 128 suitably connected to the frame of the machine. Roll support members rotatably support the shaft 130. Piston 58 is also supported by the I-beam 128 through a flange member 132. As described herein when the longitudinal mechanism is stopped the piston is actuated to push rod 134 upwardly to cause thelifterlmembe'rs to raise the hotr oll.44..

FIGS. 7-14 show various forms of the preheaters 38 in the fabric heating positionand the inoperative position.

' It should be noted in all forms of the preheaters that the shutters are spring biased to the position Where the lamps will be exposed to the heat sink'in order to prevent a fire and/orscorching of the fabric upon a stopping or malfunctioning of the machine. It :also is .preferred to keep the infrared lamps continuouslyoperating so that time will'not be lost during shutdown and startup of the lamp.

FIGS. 7 and 8 showthe preferred form of preheater .38. .FIG. 7 shows the position of the lamp reflectors 136 when piston .40 has been actuatedto rotate the reflector 136 to the position shown against the bias of spring 138 to direct the days of the infrared elements 140 onto the fabric 14 through the elongated. slot 142 in the reflector 136 to the position shown against the bias of spring 138 to direct the rays of the infrared elements1140fonto the fabric 14 through the elongated. slot 142 in the reflector 136. When the pressure has been relieved on the piston 40 the spring 138 will pull the cable 143 to rotate the reflector 136 to the position shown in FIG. 8 to direct the lamps rays to heat sink or heat exchanger 144 to thereby take theheat off the fabric 14 in response to. a control (not shown) actuated by a fabric temperature sensing device (not shown). The' c'able 143 is suitably guided by idler rolls 146 while the reflector 136is guided byrollr bearings. 148. It should bejno'ted that roller bearing 150 is mounted on a lever arm 152 pivoted at 154' and biased toward the reflector 136 by spring 156. This is to automatically compensate for expansion and contraction of the reflector due to the change in temperature.

FIGS1'9-1l show a modified preheater similar to that schematically shown in FIG. 1.. FIG. 9 shows in detail the preheater 38 which consists basically of the infrared element 140 and reflector halves 158 pivotally mounted at 160 and biased to the inoperative position shown in FIG. 11 by springs 162 connected to a suitable support 164. Mounted on the supports is a pulley 166 to guide the cables 168 attached at one end to the pistons 40 and at the other end to the reflector halve 158.

FIG. 10 represents the preheater 38 when the piston 40 has been actuated to pull the cables 168 to pivot the reflectors 158 to a position where the elements 140 are exposed to the fabric 14 through the opening 170. FIG. 11 represents the preheater when the piston 40 has been exhausted and the springs 162 have rotated the reflectors 158 about pivot 160 to the position where the elements 140 are exposed to the heat sink 144, thereby cutting the heat off from the fabric.

FIGS. 12-14 schematically represent another form of the preheater which will maintain constant preheat temperature at various speeds of the fabric. Essentially this form consists of an elongated element 140 and refiectors 172 controlled individually by shutters 174 to allow portions of the element to be exposed to fabric 14. Basically this modification allows the speed of the fabric 14 to be varied with a constant preheat temperature. This is accomplished by exposing more of the element area as the speed of the fabric is increased or closing off a portion of the element 140 upon a reduction of the speed of the fabric. This operation is preferably automatic and the positions of the shutters will be automatically varied in response to speed of the fabric and the temperature of the fabric.

FIG. 15 is a view similar to FIG. 1 schematically representing a system in which the longitudinally seal and slit fabric is taken up on a fabric takeup roll 176 preferably driven by surface drive rolls 178. In this form of the invention when the fabric is taken up on a takeup roll rather than being transversely sealed and cut, it is normally necessary to cool the fabric to set the seal 49 therein since the takeup speed in this form is much greater and the seal 49 does not have sufiicient time to cool. There for e, from the cutter 70 the fabric is delivered over' cooling rolls 180 prior to delivery to the fabric; take: up 176. The number and type of coolingbeing dependent basically orith'e temperature and speed Qfthe fabric,

"It can readily be seen that we have" provided a method and apparatusj to efiiciently provide at least two'l'engths of [fabric from aisirigle length of fabric which has the sjelvag'esautomatically sealed against raveling'without the additionaljtedious step'of hemming the fabric after it has e n ti now poss to Wave an k it wid 'w hs of fabric and automatically providing a plurality of narrower widths of fabric withoutgwea'ving' or hemming in' a selvag'e to prevent raveling. This, of course, is moreeffiqent since it is cheaper to produce a certain numberiof lengths of fabric from one machine rather than'produce the samepumber' of lengths of fabric on diife're it m'a-j h ne -v v ,Although the preferred embodiments of the inventio'n have been described in detail, it is contemplated that iiiany changes mayfbe made without departing f'riomthe scope or spirit of the'invention and it is' desiredto be limited only by thefclaims.

That which is claimed is: v I, I 5 s ,1, Apparatus to' continuouslyj provide a length of fabric with a sealed selvage' comprising: a pair 'of ro'lls iri-nip forming relationship withnat least one of said rolls. being heated, mean's'to' supplylfabric into the nip of said rolls, means to preheat the fabric prior to supplying, into the nip of said rolls, m'ean s' separate fromthe fabric tolsupply a narrow thermoplastic strip. of film onto said fabric in the nip of said rolls in the direction of travel of said fabric,

said film strip supply means including a meansito wrap the narrow strip of film around a portion of the peripheral surface of said heated roll prior to being supplied into the nip of said rolls and means operably associated with said apparatus to sever the fabric through the narrow strip of film after it has been sealed to the fabric.

{2, The apparatus of claim 1 wherein the means to wrap the'film around a portion of the heated roll'is adjil'stableto vary the amount of wrap.

' The'apparat'us of claim 1 wherein said fabric supply preheater means includes a'source of heat and a reflector therearound to reflectthe heat onto the fabric and a means to divert the reflection of heat away from said fabric when desired, said deflector means being segmented and includ- :means to pr'ovide incremental portion s of the heat from said heat source on the fabricf 7 References Cited ,UNITED STATES PATENTS 8/ 1966; .Olstad 156-271 3,707,419412/1972 Coburn 156-88 3,385,747 5/1968 Klein et al-. t 156-88 73,108,034 10/1963 Hannon 156-582 3,060,077 10/1 962- Kauer 156-322 2,954,069 9/1960 Lithio 156-499 3,030,244 v:- 4/1962 Waite 156-499 73,180,778 4/1965 Rinderspacher et a1. 156-322 5 I FOREIGN PATENTS 1,083,220 6/ 1960 Germany 156-499 DOUGLAS J.- DRUMMOND, Pm'r Examiner 1 r us. 01; X.R. 156-510,-5'54 I

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